This research will increase the understanding of the cortical processing of thalamic inputs in the auditory system. Effort will be devoted to experiments designed to understand auditory physiological phenomena such as cortical receptive field formation, ability of cortical neurons to entrain to a stimulus train, and integration of complex stimuli. Using an auditory thalamocortical slice containing the primary auditory pathway the spread of excitation and the temporal processing ability of cortical networks in response to focal stimulation of the ventral division of the medial geniculate body will be investigated. These experiments will involve field potential recordings horizontally across layer 4 and throughout the cortical laminae, with concurrent whole-cell patch recordings in layer 4 and anatomical analysis of recorded cells filled with biocytin. Experiments will also be performed to determine how spatial activation of auditory cortex combines with the temporal processing ability of layer 3/4 neurons to dictate the optimal stimulus configuration for individual neurons (e.g., simulated FM stimulus). Two focal stimuli will be delivered to the thalamus and the response of a given cortical cell to synchronous and asynchronous stimulation will be recorded. By increasing the understanding of cortical mechanisms in processing, auditory stimuli researchers will be able to advance treatments for the hearing impaired.